Admitting Expert Testimony in Injury Trials

A personal injury trial can require knowledge of much more than just personal injury laws. A lawyer often needs to present argument and testimony that go beyond law and into varying fields of expertise.

A medical malpractice case will require argument about medicine and anatomy. Negligent security cases may require testimony about generally accepted security procedures. Slip and falls may require argument about building codes. Any case involving a product may require knowledge of how the product is assembled. These are all areas that are often outside the technical expertise of both lawyers and juries.

Using Experts

This is why experts come into play, and why their testimony is so crucial to explaining a case to a jury. Many people believe that an expert can walk in, testify, and have it accepted by the court, but there are actually strict requirements to how such testimony is used and how to get it admitted.

The first step in having an expert testify for you is to make sure the witness is qualified as an expert. A judge will evaluate the credentials, resume, and history of your expert, and if the expert is qualified, the court will qualify them to provide expert testimony.

This is usually the easy part because most attorneys on both sides only hire expert witnesses with proper credentials. It is not hard to look at a resume and determine whether someone has the requisite background to be an expert.

Generally, an expert’s final opinion is not the part that determines whether the testimony is admitted and heard by a jury or excluded. The legal tests focus more on the process and procedure of the expert—how the expert reached her conclusion.

The court will look to the methodology, process, and procedures that the expert used to come to her conclusion, to make sure that the process is generally accepted within the scientific community. This requires a heavy focus on each step in the testing process that the expert used.

Did the expert rely upon methods that are used often or upon experimental techniques? Are there problems in the procedures that the expert used? Do other people in the same field come to conclusions the same way? Did the expert rely upon accepted, reviewed, and published materials? These are all questions that challenge an expert’s methodology.

Using Similar Facts

An expert also must use facts that are similar to the case. The scenario that the expert is testing must exactly replicate the circumstances of the accident. The testimony of an expert who determines that a four-foot railing around a pool is unsafe, may be inadmissible if the case involved a five-foot fence.

Often, the expert is basing his opinion on variables like space, time, or distance, based only on the observations of lay witnesses. This can also cause problems with admissibility, if those opinions are unreliable.